wire sniffer

The conflict domain and CSMA/CD take the 10 m Switch and Hub as an example. Each port of a vswitch is an independent conflict domain. If the port is connected to only one machine, there will be no conflict and the bandwidth is only 10 Mbps. If it is a HUB, all ports are in a conflict domain, and all machines share 10 Mbps of bandwidth. Reclarify that when port A> port B sends data, the Hub sends the data to all ports, and the switch sends data to port B only through the switch chip,

unfamiliar processes. Scan your computer with the latest antivirus software. Clean up temporary files, defragment disks, and check virtual memory size. Second, the network environment 1. Is it clear that it is slow to visit a Web site, or is it slow to visit all sites? If you are only slow to visit a website, you should determine if the Web server is low on bandwidth or too heavy load. 2. Is it related to the time period? Generally afternoon and evening, relative to the morning, the speed is

TCPDUMP introduction in traditional network analysis and testing technologies, sniffer is the most common and important technology. Sniffer is designed for network analysis by network administrators and network programmers. Network administrators can keep abreast of the actual network conditions when network performance drops sharply, About TCPDUMP In traditional network analysis and testing technologies,

users in the Web surfing, Each of these users can accept Web pages at the full rate of the downstream rate, because users rarely request pages at exactly the same time. DSL advocates sharply that DSL establishes a point-to-point connection between the home and the ISP, so all DSLs are private rather than shared. Proponents of HFC say that a reasonable range of HFC networks provides greater bandwidth than DSL. 2. Company Access In corporate and university campuses, local area networks (LANs) ar

Add_mac_head (4 input CLK, 5 input rst_n, 6 input [31:0] App_Data, 7 input APP_DATA_VLD, 8 input app_data_sop, 9 input app_data_eop, input [1:0] app_data_mod,//Invalid number of bytes 11 Input MAC_TX_RDY,//MAC IP send ready signal output reg [31:0] mac_data, output reg MAC_DATA_VLD, OUTPU T reg Mac_data_sop, output reg Mac_data_eop, Output reg [1:0] mac_data_mod 18); reg [34:0] wdata; Reg Wrreq,rdreq; Reg WDATA_XX; WRREQ_XX,RDREQ_XX reg; reg [1:0] head_cnt; Reg HEAD_FLAG,HEAD_TMP,RD_FLAG,RD_F

combination of two single laminates, each of which has electronic components and cables. Sometimes you need to connect one side of the single line to the other side of the board, this is through the guide hole (). The guide hole is a small hole on the PCB that is filled with or coated with metal. It can be connected to both sides of the wire. Currently, many computer boards use 4-or even 6-layer PCB boards, while graphics cards generally use 6-layer

generating IP packets, such as sendip, Nessus, ipsend, ippacket, And sniffer, The following describes three commonly used tools: sendip, Nessus, And sniffer. 2.1. sendip Tool Sendip is a command line tool in Linux. IP packet, which has a large number of command line parameters to specify the header formats of various protocols. Currently, NTP, BGP, Rip, ripng, TCP, UDP, ICMP or raw IPv4 and IPv6 packet for

Resolution and MAC address resolution. Generally, network communication needs to be analyzed through arp, ARP queries are performed when any host is connected to the network and communicates with each other. Enter the Command Prompt window and enter the ARP-a command. ARP-A is a command to display the ARP cache information of the current host. It can be clearly displayed in this list if any other host has performed ARP queries, ARP-A displays the host's IP address, MAC address, and other inform

In the enterprise environment to build an FTP server for enterprise employees to share the convenience of the file. However, as a network administrator, do you really understand the security of FTP? Do not think that set a complex administrator account password can be all right, do not think that the system installed on the latest patches or choose the most new version of Serv-u and other FTP building tools can be foolproof. Here we will verify that FTP is not secure and provide encryption secur

When dealing with computer networks, it is inevitable that network cables should be used frequently. In fact, the production of Network cables is very simple, that is, to insert the 4-to-8-Core Cable of twisted pair wires into the crystal head according to certain rules, therefore, the materials required for the production of such network cables only need twisted pair wires and crystal heads. The required tools are also relatively simple. Generally, only one dedicated crimping clamp is required.

Downloading files from an FTP site is currently one of the most common file transfer methods. Especially for enterprise users, the company has established a dedicated FTP server for employees, it is the most convenient way for them to share resources through this server. But do you really understand FTP security as a network administrator? Don't think that setting up a Complex Administrator account password can be everything, do not think that the system installed on the latest patch or choose t

generated, you need to use the TCP sharding capability for data transmission. ◇ Data is synchronized between the master server and the slave server. As a small and unreliable transport layer protocol, UDP does not have a traffic control mechanism. When there are too many incoming packets, the receiving end may overflow. In addition to the checksum, UDP also has no error control mechanism, which means that the sender does not know whether the data is lost or repeated delivery. When the acceptor

Downloading files from an FTP site is currently one of the most common file transfer methods. Especially for enterprise users, the company has established a dedicated FTP server for employees, it is the most convenient way for them to share resources through this server. But do you really understand FTP security as a network administrator? Do not worry about setting a Complex Administrator Account or password, or install the latest patch on the system or select the latest version.SERV-UThe FTP b

standards "electrical installation engineering construction and acceptance code" provisions. Wiring, should be in accordance with the current national standards, "Fire automatic alarm system Design Code", the type of wire, voltage grade check. Fire automatic alarm system transmission line and 50V power supply control line, should be used voltage grade not less than AC 250V copper core insulated conductor or copper conductor cable. The AC 220/380v pow

not available in a single line, only one power supply can be introduced. For the typical structure of the AT traction network auxiliary partition Institute (SSP), see. In the figure, T is the catenary, F is the positive feeder, PW is the protection wire in parallel with the rail, B is the circuit breaker, SD is the security grounding device, and La is the lightning arrester; ot is the control circuit power supply; Pt is the voltage transformer; at is

data frame has multiple formats. I am afraid many people are not very clear about it, the purpose of this article is to distinguish between the frame format and the packet decoding captured by sniffer. Ethernet generally refers to digital devicesEquipment), Intel, and Xerox jointly announced a standard in 1982 (in fact, it is the second version, the first version as early as 1972It was generated in Parc at Xerox's Palo Alto Research Center ). It is c

About I2C, this is also the previously tangled part. Note. (For details, refer to: source; Phodal'sBlog) The I2C (Inter-Integrated Circuit) bus is a two-line serial bus developed by PHILIPS to connect the microcontroller and its peripheral devices. It is a bus standard widely used in the field of microelectronics communication control. > The I2C bus supports any IC production process (nmos cmos, bipolar ). Two-wire-the serial data (SDA) and serial clo

-seqno ack window urgentoptionsSrc> dst: Indicates from the source address to the destination address. flags indicates the flag information in the TCP packet, S indicates the SYN mark, F (FIN), P (PUSH), R (RST )". "(not marked); data-seqno is the sequence number of data in the data packet, ack is the sequence number expected next time, window is the size of the window that receives the cache, and urgent indicates whether there is an emergency pointer in the data packet. options is an option. (4

With the popularity of broadband, a lot of people choose to watch the video directly online, especially to watch some recently released movies or enjoy the popular video sharing sites, such as potatoes, cool, and so on. But sometimes encounter wonderful video will want to save, this kind of demand also exists in a lot of slow friends, online watch video card of the deadly, for them difficult to accept, there is no way to download the online video to watch it? In fact, We can use a special way to

thinker 3800 reach 100% wire speeds in 512-byte, 1518-byte frames, and are not up to the line speed for only 64-byte frames. A fully meshed test environment is stricter than a one-to-one environment for throughput, requiring each port in the switch to receive data sent from other ports, as well as sending data to other ports, but 3Com 4900, Shenzhou digital D-link DGS-3308TG and Edimax ES-5800R these three excellent switches remain the same color, d